1. Field of the Invention
The present invention relates to bar code symbol reading devices that provide data to one or more host systems (for example, personal computers, point-of-sale (POS) stations, inventory management systems, document tracking systems, package tracking (and routing and delivery) systems, other retail solutions (such as price look-up kiosks), etc.)
2. Brief Description of the Prior Art
Bar code symbols have become widely used in many environments such as, for example, as a form of data input to personal computers, point-of-sale (POS) stations, inventory management systems, document tracking system, package tracking (and routing and delivery) systems, other retail solutions (such as price look-up kiosks), a diverse range of data acquisition and control applications, etc.). To meet the growing demands of this technological innovation, bar code symbol readers of various types have been developed for reading bar code symbols and producing symbol character data for use as input in such automated data processing systems.
In general, it is desirable to enable a bar code symbol reading device to interface to a variety of different host devices. This feature allows the bar code symbol reading device to be used in a variety of applications that utilize such different host devices. Moreover, it is desirable to make the configuration of such an interface automatic with minimal human involvement.
Heretofore, several mechanisms for interfacing bar code symbol reading devices to host systems have been proposed.
Many commercially available bar code symbol reading devices distribute configuration manuals (or guides) that include bar code labels for different device-host configurations (and parameters). The bar code labels encode data, which is read by the bar code scanning device and used in an internal configuration routine to select and configure the interface between the bar code scanning device and the host system. Whenever the user desires to use the scanning device with a different host system, the user must locate the appropriate guide/label and read the data encoded by the label, which may be problematic in the event that the user has misplaced (or lost) the guide/label or an error occurs in the label reading operation.
In U.S. Pat. No. 5,258,604, a system is disclosed which implements a bar code scanning device which is configured to accept any of a plurality of differently configured interface boards in its handle, wherein each type of interface board is specially adapted to mate with an associated host device. The decoder in the scanner polls the interface board upon power-up and reads an identification code from the particular interface board which the user has inserted. The identification code is used by the decoder to access configuration and formatting data from an on-board memory in order to transmit data to the interface board and ultimately to the host device in the required manner. This requires a user to have to swap electrical boards inside the scanner device whenever he desires to use the scanner with a different host device, which is unwieldy and potentially damaging to the boards due to electrostatic discharge (ESD) phenomena.
In U.S. Pat. No. 5,875,415, a system is disclosed which implements a bar code scanning device that formats bar code symbol character data into a specific SDCI data format. An interface cable, which is specific to a given type of host device, includes a host protocol and translation means that configures the bar code symbol data in the SDCI format into a format required by the given type of host device and transmits such data to the host device. Note that each different type of host device will require the use of a differently configured interface cable in order to enable communication between the bar code scanning device and host device, thus greatly increasing the cost of the interface cables themselves. Moreover, whenever the user desires to use the scanning device with a different host system, the user must locate (or purchase) the appropriate interface cable, which may be problematic and costly in the event that the user has misplaced (or lost) the required interface cable.
In U.S. Pat. No. 5,905,249, a system is disclosed which provides different connecting cables and labels for different bar code scanning devices/host system pairs. The labels are bar code labels (or RFID tags) that encode data which is read by the bar code scanning device and used in an internal configuration routine to configure the parameters of the interface between the bar code scanning device and the host system, such as baud rate, data format settings, hardware land software handshaking, UPC data format, etc.). Whenever the user desires to use the scanning device with a different host system, the user must locate (or purchase) the appropriate interface cable/label and read the data encoded by the label, which may be problematic in the event that the user has misplaced (or lost) the label for the cable or an error occurs in the label leading operation.
Thus, there is a great need in the art for a bar code reading device with an improved communication interface that enable the bar code symbol reading device to interface to a variety of different host devices in an automatic and error free manner with minimal human involvement.
Accordingly, it is a primary object of the present invention to provide an improved method of and device for reading bar code symbols that performs automatic configuration of a communication interface of the device to thereby enable a data communication link between the device and a host system, while overcoming the above described shortcomings and drawbacks of prior art devices and techniques.
A further object of the present invention is to provide such a device that implements a plurality of different communication interfaces and operates, during an interface configuration mode, to automatically select at least one of the plurality of different communication interfaces and test each selected communication interface to ascertain if the given communication interface corresponds to the communication interface of the host system.
A further object of the present invention is to provide a device that carries out such automatic interface configuration operations when the device is initially powered up.
A further object of the present invention is to provide a device that carries out such automatic interface configuration operations to enable subsequent data communication between the device and the host system.
It is yet another object of the present invention to provide a device that carries out such automatic interface configuration operations to provide a versatile bar code symbol reading device that is capable of operably interfacing to a plurality of diverse host systems with minimal human involvement in configuring such diverse interfaces.
It is yet another object of the present invention to provide a device that carries out such automatic interface configuration operations, in which the enabled communication interface of the device and the communication interface of the host system provides a wireless data link (such as an infra-red link, a Bluetooth RF link, and an IEEE 802.11b RF link) between the device and the host system.
A further object of the present invention is to provide a device that carries out such automatic interface configuration operations, in which the enabled communication interface of the device and the communication interface of the host system provides a wired serial data link (such as a keyboard wedge link, an RS-232 link, USB link, an IEEE 1394 link, an RS-422 link, and a RS-485 link) between the device and the host system.
A further object of the present invention is to provide a device that carries out such automatic interface configuration operations, in which the enabled communication interface of the device and the communication interface of the host system provides a standard communication link (such an OCIA link, an IBM 46XX link, a Light Pen Emulation link, and a LTPN link) between the device and the host system.
It is yet another object of the present invention to provide a device that carries out such automatic interface configuration operations, in which the reading of a bar code symbol and subsequent communication of the symbol character data corresponding thereto to the host system occurs automatically without the need for human interaction to activate such operations.
A further object of the present invention is to provide a device that carries out such automatic interface configuration operations, in which the reading of the bar code symbol occurs automatically without the need for human interaction to activate such operation, and the subsequent transfer of the symbol data corresponding thereto to the host system is manually-activated by a user interaction with a data transmission switch.
A further object of the present invention is to provide a device that carries out such automatic interface configuration operations, in which the reading of the bar code symbol and the subsequent transfer of the symbol data corresponding thereto to the host system is manually-activated by user interaction with a trigger mechanism.
It is yet another object of the present invention to provide a bar code symbol reading device that maintains a status register that stores information related to the establishment of a communication link between the device and a host system over a specific interface implemented by the device, and wherein the device reads the information stored in said status register during automatic configuration of the communication interfaces implemented by the device.
It is yet another object of the present invention to provide a bar code symbol reading device that maintains a status register that stores information indicative of the exchange of determined data packets in an enumeration sequence that establishes a communication link between the device and a host system over a specific interface implemented by the device, and wherein the device reads the information stored in said status register during automatic configuration of the communication interfaces implemented by the device.
It is yet another object of the present invention to provide a bar code symbol reading device that tests the signal levels of a given communication interface implemented by the device during automatic configuration of the communication interfaces implemented by the device.
It is yet another object of the present invention to embody a subsystem that carries out such automatic interface configuration operations in a wand-type scanner, hand-held scanner, presentation scanner, electronic cash register systems and other point-of-sale terminals, other retail solutions such as price look-up kiosks, and data acquisition systems (for example, those involving inventory control, patient care in hospitals and other medical applications).
These and further objects of the present invention will become apparent hereinafter and in the claims to Invention.